200304496 (1) 玖、發明說明 【發明所屬之技術領域】 本發明係有關鎂合金之成形方法，係將鎂合金鑄造， 並將該鑄造品鍛造成所欲形狀者。 【先前技術】 由於鎂（Mg )之比重1 . 8，較作爲輕量金屬代表其比 重爲2 · 7之鋁（A1 )更小，因此鎂合金非常輕。而且鎂合 金之比鋼性較鋁合金爲高，熱傳導性亦優越，因此可作爲 電器、電子機器之外框、零件之構成材料廣泛使用。 然而，由於鎂合金爲難加工性之物，有不易成形爲所 欲形狀之缺點。亦即因鎂合金之凝固潛熱小凝固速度快而 鑄造困難，且所得鑄造品有容易產生巢紋或水紋般缺陷之 缺點。因此，特別是重視外觀之製品其良率降低，且由於 必須將缺陷施予油灰處理而有成本提高之問題。由於鎂合 金爲最密六方晶型而延性低，將板材或棒材施予壓力或鍛 造加工之際必須於3 00-5 00 °C之高溫下進行，因此有加工 速度遲緩、步驟增多、鑄模壽命短等問題。 爲解決此種鎂合金難加工性之問題，日本特開平7-2 24 3 44號公報揭示於將其組成爲鋁含量6.2-7.6重量％之AZ 系鎂合金連續鑄造而獲得小合金塊之步驟中，藉由添加微 細化劑及/或控制冷卻速度而使小合金塊之平均結晶粒徑 成爲200 μηι以下，並將該小合金塊鍛造而製造大型零件之 方法。該公報亦揭示加工成爲最終製品形狀後’藉由組合 (2) (2)200304496 溶體化處理與T6熱處理，使平均結晶粒徑成爲50 μπι以下 而提高耐蝕性。 另一方面，日本特開200 1 -294966號公報揭示藉由壓 鑄法或觸變模鑄成形機使鎂合金成形爲板狀，將該板材於 常溫壓延賦予應變性後，於3 5 0-400 °C加熱使結晶再結晶 化，藉由使結晶粒徑微細化至0.1-30 μπι而提昇延性，並 將延性提昇之板材施予加壓加工或鍛造而成形之方法。又 ，日本特開200 1 - 1 70734號公報及同公報1 7073 6號揭示， 將鎂合金之板材鍛造成型，藉粗鍛造與最後加工鍛造之多 個步驟使成形爲其高度爲主要部分厚度之7倍或10倍以下 之鑄造品之方法。 然而，以鎂合金成形爲複雜且形狀精密之零件時，如 日本特開平7_22 4 3 44號公報所揭示，由小合金塊鍛造之方 法其形狀、厚度方面有其限度，另一方面，如日本特開 200 1 _294966號公報、同公報1 70734號及同公報1 7073 6號 所揭示，由鎂合金之板材成形之方法，雖可製造較薄零件 ，但欲將該板材施予加壓加工或鍛造而獲得複雜且形狀精 密之成形品則甚爲困難。 近年來對有關鎂合金與鋁合金同樣之超塑性之表現機 制已很淸楚，顯示藉由使結晶粒徑微細化而可在高應變速 度下加工之可能性（例如「鎂技術便覽」第1 1 9-1 25頁） 〇 一般而言，將合金成形爲複雜且精密之形狀時，以使 用如壓鑄法之射出速度，亦即充塡速度快之鑄造法爲佳。 -8- (3) (3)200304496 然而，如前述般由於鎂合金易凝固，使用壓鑄法等鑄造法 易產生水紋，且因視形狀而難以充塡至鑄模之各角落，而 使成形品之大小、厚度受限。此外，若射出速度增快則鑄 液中易捲入空氣或氣體而產生巢紋，而有物性可性度之問 題。 另一方面，將該板材加壓加工時雖可成形爲與板材寬 度同大之製品，但由於鎂合金爲延性低且難加工性者，欲 形成複雜之形狀，例如欲同樣鑄造形成鑄造品甚爲困難。 就合金組成方面而言，鎂合金之鑄造性與展延性爲表 裡關係，鑄造材可選擇因鋁含量多其融熔溫度降低而容易 鑄造之AZ91、AM50、AM60材等使用，又，壓鑄•鍛造材 可選擇鋁含量少而延性高之AZ3 1材使用。耐蝕性方面則 鋁含量多者耐鈾性優越。因此與AZ91材相較AZ31材之耐 蝕性較差，此亦爲AZ3 1材用途狹窄理由之一。 【發明內容】 本發明有鑑於上述以往之實況，其目的在提供鎂合金 之成形方法，係於可鑄造且鍛造性優越之鎂合金組成中， 藉由組合鑄造與鍛造使鎂合金成形，並以高良率製造具有 複雜而精密之形狀，且物性可信度高，耐蝕性亦充分足夠 之製品。 本發明係有關： 1 ♦一種鎂合金之成形方法，其特徵爲將鋁含量爲2-10質量％之鎂合金鑄造而獲得結晶粒徑30 μηι以下之鑄造 (4) 200304496 品’將該鑄造品以其組成之固溶溫度與固相線範圍 進行溶體化處理後，鍛造而得結晶粒徑1 0 μηι以下 品，再將該鍛造品進一步鍛造成所欲之形狀者。 2. 上述項1之錢合金之成形方法，其中，該鏡 銘含量爲2.5 - 6質量°/〇者。 3. 上述1或2項之鎂合金之成形方法，其中， 係以壓鑄法或觸變模鑄法進行者。 4. 上述1至3項中任一項之鎂合金之成形方法 ，該溶體化處理係於3 8 0至4 4 0 °C下進行1 - 2 4小時者 5. 上述1至4項中任一項之鎂合金之成形方法 ’係於Z値爲1 0 9 -1 0 13之應變速度及溫度條件下進行 得結晶粒徑1 ο μ ΠΊ以下之結晶粒微細化鍛造品者。 6. 上述1至5項中任一項之鎂合金之成形方法 ’結晶粒微細化鍛造品係於Ζ値爲1 〇 1 3之應變速度 條件下鍛造成爲所欲形狀者。 1' 一種鎂合金之成形方法，其特徵爲將鋁含 1 〇質量％之鎂合金纟#造而獲得結晶粒徑i 〇 μ m以下 品’將該鑄造品以其組成之固溶溫度與固相線範圍 進行溶體化處理後，鍛造成所欲之形狀者。 8.上述第7項之鎂合金之成形方法，其中，該 之鋁含量爲2-6質量％者。 9·上述第7或8項之鎂合金之成形方法，其中 造係以壓鑄法進行者。 10.上述第7至9項中任一項之鎂合金之成形方 之溫度 之锻造 合金之 該鑄造 ，其中 〇 ，其中 锻造而 ，其中 及溫度 量爲2- 之鑄造 之溫度 錶合金 ，該鑄 法，其 -10- (5) (5)200304496 中，該溶體化處理係於380至44〇°C下進行1-24小時者。 11.上述第7至10項中任一項之鎂合金之成形方法， 其中，係於Z値小於1 〇 1 3之應變速度及溫度條件下進行鍛 造者。 如上述第1項之鎂合金之成形方法，其特徵爲將鋁含 里爲2-10質星％之鎂合金纟尋造而得結晶粒徑3〇 μπ!以下之 鑄造品’再將該鑄造品於其組成之固溶溫度與固相線範 圍之溫度進行溶體化處理後，鍛造而得結晶粒徑1 〇 μηι# 下之鍛造品，然後再將該鍛造品進一步鍛造成所欲之形 狀。 將藉由鑄造作成結晶粒徑3 0 μηι以下之鑄造品施予溶 體化處理時，則鑄造時原來形成之粗大且脆弱晶界之第2 相粒子消失而伸展性增大，塑性加工性提昇。藉由此種溶 體化處理而鍛造塑性加工性提昇之鑄造品，可藉由鍛造使 動態再結晶而使結晶粒徑微細化至1 0 μιη以下，而進一步 提高其锻造成形性。因此，以第1項之方法，將藉由鑄造 而成爲結晶粒徑3 0 μιη以下之鑄造品施予溶體化處理，然 後藉由鍛造使結晶粒徑成爲10 μπι以下，再進一步鍛造成 所欲之形狀。 於該方法中，鎂合金之鋁含量以2.5-6質量％爲佳，而 鑄造係以壓鑄法或觸變模鑄法進行爲佳。又，溶體化處理 以於3 80至440°C下進行1-24小時爲佳，溶體化處理後爲使 結晶粒微細化之鍛造及其後爲成形之鍛造以於Z値1〇9-1〇 13 之應變速度及溫度條件下進行爲佳。 -11 - (6) (6)200304496 上述第7項之鎂合金之成形方法，其特徵爲將鋁含量 爲2-10質量％之鎂合金鑄造而獲得結晶粒徑10 μιη以下之 鑄造品，再將該鑄造品以其組成之固溶溫度與固相線範圍 之溫度進行溶體化處理，然後鍛造成所欲之形狀。 將藉由鑄造而成爲結晶粒徑1 0 μπι以下之鑄造品施予 溶體化處理時，雖結晶粒粗大化，但鑄造時形成之粗大且 脆弱晶界之第2相粒子消失而伸展性增大，塑性加工性提 昇。藉由鍛造此種經溶體化處理而塑性加工性提昇之鑄造 品，可成形爲所欲之形狀。因此，以上述第7項之方法， 將藉由鑄造而製得之結晶粒徑1 0 μπι以下之鑄造品施予 溶體化處理，然後藉由鍛造製成所欲之形狀。 於該方法中，鎂合金之鋁含量以2-6質量％爲佳，而 鑄造係以壓鑄法或觸變模鑄法進行爲佳。又，溶體化處理 以於3 80至440°C下進行1-24小時爲佳，而其後爲了成形之 鍛造以於Z値小於10i3之應變速度及溫度之條件下進行爲 佳。 Z値係指表示溫度與應變速度之關係之溫度補償應變 速度’係一般常用於表示達到流動應力之溫度與應變速度 之效果關係式之吉諾-霍落蒙（Zener-Hollomon)參數， 可以下述式（I)定義之。 Ζ= ε ’exp ( Q/RT ) ........ ( I ) 此處， ε '應變速度（sec-i ) Q:晶格擴散活性化能 -12- (7) (7)200304496 R:氣體常數 T :絕對溫度 Q値因無法求得鎂合金之値一般係使用純鎂之！ 3 5千 焦耳/莫耳。 【實施方式】 下文詳細說明本發明鎂合金成形方法之實施方式。 首先說明上述第1項之鎂合金成形方法之實施方式。 以上述第1項之方法，先將鋁含量爲2- 1 0質量％之鎂 合金鑄造而獲得結晶粒徑30 μιη以下之鑄造品。 該鎂合金之銘含量若小於2質量％則成爲耐蝕性低劣 之物’且因融熔溫度變高而不適宜鑄造。鎂合金之鋁含量 若大於1 〇質量％則藉由後續之溶體化處理無法充分提高塑 性加工性，而無法獲得鍛造性優越之溶體化處理品。因此 ’錢合金之銘含量爲2-10質量％，較好爲2.5-6質量％。 此種鎂合金之鑄造法並無特別限制，但爲獲得結晶粒 徑3 0 μ m以下之鑄造品，以採用冷卻•凝固速度較快，且 可將結晶粒微細化之壓鑄法或觸變模鑄法佳。 亦即，重力鑄造法一般係視產品厚度而融溶鎂合金之 凝固緩慢，因此於冷卻•凝固期間結晶成長而結晶粒徑粗 大達200 μπι，而如壓鑄法或觸變模鑄法，則係將鑄模內融 熔或半融熔狀態之鑄液射出之鑄造法，其冷卻•凝固速度 快因此結晶粒微細化，而可鑄造成爲結晶粒徑3 0 μ m以下 -13- (8) 200304496 繪造品以結晶粒徑小者爲佳，3 0 μ m以下 用之is法及合金組成一*般係鏡造成爲結晶粒 者。 藉由f尋造而得之結晶粒徑30 μιη以下之禱 進行溶體化處理。 溶體化處理溫度係於其組成之固溶溫度與 之溫度即可，最適溫度爲3 80至43 0 °C。溶體化 於固溶溫度或小於3 8CTC，則因析出鋁或鎂之 而妨礙塑性加工性，若超過其組成之固溶溫g t，則產生液相而妨礙塑性加工性。溶體化處 24小時爲宜，溫度低時以較長時間，溫度高時 爲佳。藉由溶體化處理則析出於母相α相之結 相溶解於母相，雖母相之結晶粒粗大化但藉由 性加工性之晶界滑動之石相可獲得提高加工性 溶體化處理後，進行鍛造而獲得結晶粒徑 之鍛造品（下文，亦將此用於結晶粒微細化之 結晶粒微細化鍛造」）’再將該鍛造品鍛造成 狀而獲得製品（下文，亦將此用於鍛造成形爲 鍛造稱爲「成形鍛造」）。 結晶粒微細化鍛造係藉由動態再結晶化將 晶粒微細化者，該結晶粒微細化鍛造或成形鍛 合金之組成而於可鍛造加工之條件範圍內進行 結晶粒微細化鍛造之條件雖視鎂合金之組 以Ζ値爲1〇9-1〇13之範圍，較好爲i〇1Q-i〇13之範 即佳，視採 徑 1 5·3 0 μιη 造品，繼續 固相線範圍 處理溫度小 巨大化合物 [或超過430 理時間以1 -以較短時間 晶晶界的冷 減少阻礙塑 之效果。 1 0 μ m以下 鍛造稱爲「 爲所欲之形 所欲形狀之 鑄造品之結 造均需視鎂 〇 成而異，但 圍的應變速 -14- (9) (9)200304496 度及溫度條件下進行爲佳。 又，成形鍛造之條件雖亦視鎂合金之組成而異，但以 Z値爲1013以下，較好爲108-1013，更好爲109-1012之範圍 的應變速度及溫度條件下進行爲佳。 結晶粒微細化鍛造及成形鍛造之任一者其鍛造條件若 爲上述較佳Z値之範圍以外，則有產生破損、裂痕等缺陷 而不能鍛造之情況。 一般情況，結晶粒微細化鍛造係視合金組成而設定條 件，以應變速度lO^-lOdsecT1、溫度200-500 °C之範圍爲 上述Z値之適當範圍，成形鍛造係視合金組成而設定條件 ，以應變速度lO^-lOdsecT1、溫度200-40(TC之範圍爲上 述Z値之適當範圍。 藉由結晶粒微細化锻造使結晶粒徑成爲1 0 μ m以下， 並藉由鍛造改善塑性加工性，而可成形鍛造。該結晶粒徑 爲1 0 μηι以下即可，一般而言係施行結晶粒徑成爲約^ i 〇 μιη之結晶粒微細化鍛造。 繼之說明上述第7項之鎂合金成形方法之實施方式。 上述第7項之方法係先將鋁含量爲2- 1 〇質量％之鎂合 金鑄造而獲得結晶粒徑10 μιη以下之鑄造品。 該鎂合金之鋁含量若小於2質量％則成爲耐蝕性低劣 之物。鎂合金之纟S含量若大於1 0質量％則藉由後續之溶體 化處理無法充分提高塑性加工性，而無法獲得鍛造性優越 之溶體化處理品。因此，鎂合金之鋁含量爲2 -1 〇質量％， 較好爲2 - 6質量％。 -15- (10) (10)200304496 又，所用鎂合金之鋁以外之其他成分含量係與上述第 1項之方法中所述者相同。 此種鎂合金之鑄造法爲獲得結晶粒徑3 0 μηι以下之鑄 造品，以採用冷卻•凝固速度非常迅速，可將結晶粒微細 化之壓鑄法較佳。 鑄造品之結晶粒徑雖以小者爲佳，而1 〇 μπι以下即可 ，視採用之合金組成，一般係鑄造成爲5 - 1 0 μ m之結晶粒 徑。 藉由鑄造而獲得之結晶粒徑1 0 μιη以下之鑄造品，在 於其組成之固溶溫度與固相線範圍之溫度進行溶體化處理 ’以提高加工性。該溶體化處理條件係與上述第1項方法 之溶體化處理同樣理由，以3 80至43 0°C，1-24小時爲佳， 溶體化處理後再鍛造成爲所欲之形狀而獲得製品。 該鍛造亦與上述第1項之方法同樣，必須視鎂合金之 組成而於可鍛造加工之條件範圍進行。 鍛造之條件雖亦視鎂合金之組成而異，但以Z値小於 1〇13之範圍，較好於Z値爲10、10i2之範圍的應變速度及溫 度條件下進行’ Z値爲1〇13以上則有產生破損、裂痕等缺 陷而不能鍛造之情況。 一般彳胃況’上述鍛造係視合金組成而設定條件，以應 變速度lO^-lO^sec·1、溫度200-50(rC2範圍可使上述Z値 爲適當範圍。 〔實施例〕 -16- (11) 200304496 下文列舉實施例具體說明本發明 又，於下列實施例中所使用之鎂合金錠，係於市售之 AZ 91合金錠中添加鎂與鋅進行成分調整而製作者，據此 製作AZ8 1-AZ2 1組成之鎂合金錠。所使用之AZ91合金錠與 所製作之合金錠之成分分析結果示於表1。 表1 合金錠之成分分析結果 （質量％)_ 合金 錠 A1 Zn Μη Si C u Fe Ni Be AZ9 1 8.9 0.70 0.2 1 0.3 10 0.0400 0.0020 0.0004 0.0008 AZ8 1 7.6 0.70 0.30 0.025 0.0010 0.0017 tr 0.0034 AZ7 1 6.9 0.72 0.24 0.024 0.0011 0.0003 tr 0.0019 AZ6 1 5.7 0.79 0.30 0.024 0.0010 0.0029 tr 0.0026 AZ5 1 4.8 0.78 0.29 0.018 0.0009 0.0013 t r 0.0022 AZ4 1 3.6 0.68 0.27 0.013 0.0008 0.0012 tr 0.0014 AZ3 1 2.6 0.60 0.28 0.010 0.0004 t r tr 0.0016 AZ2 1 2.1 0.83 0.28 0.003 0.0052 tr t r 0.0030 實施例1 (1 )鑄造及溶體化處理 將AZ9 1-AZ21之合金錠硏削作成觸變模鑄用晶圓以供 鑄造。以日本製鋼所製觸變模鑄成形機JMG-45 0，設定於 空打條件下射出速度最高爲4m/sec，以鑄模溫度設定爲 25〇C之縱181mm X寬255mm X高10mm有底無蓋之箱型鑄 模製得厚度1.5mm之鑄造品。又，鑄造時，因各合金錠之 -17- (12) 200304496 融點不同，係於調整機筒與，噴嘴溫度，同時探討成形可能 之條件下進行鑄造。各合金鑄造時之機筒先端溫度示於表 2 〇 表2 觸變模鑄鑄造之機筒先端溫度 合金 溫度（°C ) AZ9 1 620 AZ8 1 6 18 AZ7 1 619 AZ61 624 AZ5 1 637 AZ4 1 640 AZ3 1 638 其結果爲AZ9 1至AZ3 1可進行鑄造，而AZ21熔點爲 64 5 °C，於成形機之加熱界線內不融熔而無法鑄造。因此 ，咸認AZ系合金之觸變模鑄成形機之鑄造界線爲鋁含量 2.5 % 〇 觸變模鑄鑄造所得鑄造品結晶粒徑之測定，係自各鑄 造品之中央部位採樣，包埋於樹脂並硏磨後，視樣品組成 以古液酸或乙酸系蝕刻劑進行蝕刻，以5 00倍電子顯微鏡 攝影，依據JIS GO 5 22之「鋼塊結晶粒度試驗法」之切片 法測定，求得之粒徑爲1.74倍。 又，爲確認溶體化處理之效果，將各鑄造品於43 0 t 熱處理1小時後，同樣測定結晶粒徑。 -18 - (13)200304496 此等結果示於袠3或第1圖。 表3 觸變鑄造之結晶粒徑 合金 結晶粒徑（μ m) 溶體化處理前 溶體化處理後 ΑΖ9 1 13.1 28.3 ΑΖ8 1 12.3 ―― 19.1 ΑΖ7 1 10.2 16.4 ΑΖ6 1 13.1 24.6 ΑΖ5 1 10.1 13.7 ΑΖ4 1 12.4 20.2 ΑΖ3 1 10.5 17.9 由表3及第1圖可知’溶體化處理前之結晶粒徑雖組成 不同差異並不大，經溶體化處理而結晶粒徑粗大化。此係 進行溶體化處理時，存在於晶界之Θ相溶解於母相之^相 而使結晶粒粗大化。咸認該結晶粒徑係鑄液急冷而凝固速 度快者粒徑小，結果如下。亦即，鋁含量由AZ 9 1至AZ 3 1 減少而熔點上升。因此，由於提高成形機先端之機筒溫度 ’藉由禱液溫度與禱模之溫度差可達到急冷效果’而有自 該溫度差小之AZ91之結晶粒徑28μηι，至溫度差大之AZ51 之結晶粒徑1 4 μπι，結晶粒徑有變小之傾向。然而，若爲 ΑΖ4 1、ΑΖ3 1時則相反的由於高溫之鑄液具有延遲冷卻之 作用，而成爲結晶粒徑較大之18-20 μπι。 又，爲檢視溶體化處理品之塑性加工性，自各鑄造品 -19- (14) (14)200304496 切割拉伸試驗片，於42(TC溶體化處理1小時後，以3〇〇°C 、應變速度1.0 X lO^secT1進行拉伸試驗，結果示於第2圖 〇 由第2圖可知，鋁含量多之AZ 91至AZ 71之伸展度較低 爲1 5 - 2 4 %，AZ 6 1至AZ 3 1之伸展度則爲4 0 %以上，塑性加 工性特別提高。 因此供鍛造之鑄造品之鋁含量範圍，就鑄造性而言以 2 5質量％以上，就加工性而言以6質量％以下爲佳。 (2)鍛造 於上述（1 )中，將以觸變模鑄法鑄造之AZ61至AZ31 之鑄造品於420°C溶體化處理1小時後，切割20mm X 20mm 之樣品以電爐均勻加熱，並置於預先在依表4所示之規定 鍛造溫度下保溫之鑄模內，以應變速度3.3 X lO^secT1之 一定條件進行鍛造。自鍛造後之樣品切出試驗片，以與上 述（1 )中之相同方法測定結晶粒徑，結果示於表4。又， 將前述應變速度代入上述（I )式中求得之Z値如表4所示 。此處適用於計算之Q値爲135仟焦耳/莫耳。表4一倂記載 各樣品鍛造前（溶體化處理後）之結晶粒徑。 -20- 200304496 m ! I溶體化處理後(鍛造前) 結晶粒徑(μπι) 24.6 13.7 20.2 17.9 鍛造後之結晶粒徑(μπι) 350 3.3xl〇·2 6.9xl09 12.9 10.0 18.8 in 300 3.3χΐσ2 6.7xl010 2 卜· 10.4 14.2 250 3.3χ10'2 l.OxlO12 * CN o 寸· 200 3.3χ10_2 2.7xl013 * * * o T—H 1—Η 3.3xl〇·2 1.5xl015 * * * * 鍛造溫度(。C) 8 Xfl g 賴 Μ m JM N AZ61 AZ51 AZ41 AZ31 mxsi 條件200304496 (1) 发明 Description of the invention [Technical field to which the invention belongs] The present invention relates to a method for forming a magnesium alloy, which is a method of casting a magnesium alloy and forging the cast product into a desired shape. [Prior art] Since the specific gravity of magnesium (Mg) is 1.8, it is smaller than aluminum (A1), which has a specific gravity of 2.7, which is a light metal, so the magnesium alloy is very light. In addition, magnesium alloys have a higher specific steel than aluminum alloys and excellent thermal conductivity. Therefore, they can be widely used as materials for outer frames and parts of electrical and electronic equipment. However, since magnesium alloys are difficult to process, they have the disadvantage that they cannot be easily formed into a desired shape. That is, because the latent heat of solidification of the magnesium alloy is small and the solidification speed is fast, the casting is difficult, and the obtained cast product has the disadvantages of easily producing nest-like or water-like defects. Therefore, in particular, the appearance-conscious products have lower yields, and there is a problem that costs must be increased because defects must be treated with putty. Because magnesium alloy has the densest hexagonal crystal form and low ductility, it must be carried out at a high temperature of 3 00-5 00 ° C when the plate or bar is subjected to pressure or forging. Therefore, the processing speed is slow, the number of steps is increased, and the mold is cast. Short life and other issues. In order to solve the problem of difficult workability of this magnesium alloy, Japanese Patent Application Laid-Open No. 7-2 24 3 44 discloses the steps of obtaining a small alloy block by continuously casting an AZ-based magnesium alloy whose composition is 6.2 to 7.6% by weight of aluminum. In addition, by adding a micronizing agent and / or controlling the cooling rate, the average crystal grain size of the small alloy ingot becomes 200 μm or less, and the small alloy ingot is forged to produce a large part. This publication also discloses that after processing into the final product shape, the corrosion resistance can be improved by combining (2) (2) 200304496 solution treatment and T6 heat treatment so that the average crystal grain size becomes 50 μm or less. On the other hand, Japanese Patent Application Laid-Open No. 200 1-294966 discloses that a magnesium alloy is formed into a plate shape by a die-casting method or a thixotropic die-casting molding machine. The method is to recrystallize the crystal by heating at ° C, to improve the ductility by making the crystal grain size fine to 0.1-30 μm, and to apply pressure processing or forging to form the sheet with improved ductility. Also, Japanese Patent Application Laid-Open No. 200 1-1 70734 and the same publication No. 1 7073 6 disclose that forging a sheet of a magnesium alloy into a shape, and forming it to have a height as a main part of thickness by a plurality of steps of rough forging and final forging. 7 times or less than 10 times the method of casting. However, when a magnesium alloy is formed into a complex and precise part, as disclosed in Japanese Patent Application Laid-Open No. 7_22 4 3 44, the method of forging a small alloy block has limitations in terms of shape and thickness. On the other hand, such as Japan Japanese Unexamined Patent Publication No. 200 1 _294966, Same Publication No. 1 70734, and Same Publication No. 1 7073 6 disclose that although a method of forming a sheet made of a magnesium alloy can produce thin parts, the sheet is intended to be subjected to pressure processing or Forging to obtain complex and precise shaped products is very difficult. In recent years, the mechanism of superplasticity similar to that of magnesium alloys and aluminum alloys has been very clear, showing the possibility of processing at high strain rates by minimizing the crystal grain size (for example, "Magnesium Technology Fact Sheet" No. 1 (1 9-1 pages 25) 〇 In general, when forming alloys into complex and precise shapes, it is better to use a casting method such as a die casting method, that is, a casting method with a high filling speed. -8- (3) (3) 200304496 However, the magnesium alloy is easy to solidify as mentioned above, and it is easy to produce water ripples using casting methods such as die-casting, and it is difficult to fill the corners of the mold due to the shape, which makes the molded product The size and thickness are limited. In addition, if the injection speed is increased, air or gas is easily entangled in the casting solution to cause nesting, and there is a problem in terms of physical properties. On the other hand, although the sheet can be formed into a product with the same width as the sheet when the sheet is press-processed, since the magnesium alloy has low ductility and is difficult to process, it is necessary to form a complex shape. For difficulties. In terms of alloy composition, the castability and ductility of magnesium alloys are in front and back. The casting materials can be selected from AZ91, AM50, AM60 materials that are easy to cast due to the high aluminum content and lower melting temperature. Also, die casting • Forging materials can be selected from AZ3 1 material with low aluminum content and high ductility. In terms of corrosion resistance, those with more aluminum content have superior uranium resistance. Therefore, compared with AZ91 material, AZ31 material has poor corrosion resistance, which is also one of the reasons for the narrow application of AZ3 material. [Summary of the Invention] The present invention has been made in view of the above-mentioned past conditions, and an object thereof is to provide a method for forming a magnesium alloy in a magnesium alloy composition that can be cast and has excellent forgeability. The magnesium alloy is formed by combining casting and forging, and High-yield products with complex and precise shapes, high reliability of physical properties, and sufficient corrosion resistance. The present invention relates to: 1 ♦ A method for forming a magnesium alloy, characterized in that a magnesium alloy having an aluminum content of 2-10% by mass is cast to obtain a cast having a crystal grain size of 30 μηι or less (4) 200304496 After solution treatment at the solid solution temperature and solid phase range of the composition, forging to obtain a product having a crystal grain size of less than 10 μηι, and further forging the forged product into a desired shape. 2. The method for forming a coin alloy according to item 1 above, wherein the content of the mirror is 2.5-6 mass ° / 〇. 3. The method for forming a magnesium alloy according to item 1 or 2 above, which is performed by a die casting method or a thixotropic die casting method. 4. The method for forming a magnesium alloy according to any one of items 1 to 3 above, the solution treatment is performed at 3 80 to 4 40 ° C for 1 to 2 4 hours 5. In the above items 1 to 4 The method for forming a magnesium alloy according to any one of the foregoing is a method of obtaining a forged product having a crystal grain size of 1 ο μ ΠΊ or less under a strain rate and a temperature condition of Z 値 of 10 9 -1 0 13. 6. The method for forming a magnesium alloy according to any one of the items 1 to 5 above. The forged product obtained by refining crystal grains is forged to a desired shape under a strain rate of Zn = 103. 1 'A method for forming a magnesium alloy, characterized in that a magnesium alloy containing aluminum at 10% by mass is produced to obtain a product having a crystal grain size of i 0 μm or less. The phase line range is forged into a desired shape after solution treatment. 8. The method for forming a magnesium alloy according to item 7 above, wherein the aluminum content is 2 to 6% by mass. 9. The method for forming a magnesium alloy according to item 7 or 8 above, wherein the fabrication is performed by a die casting method. 10. The casting of the forged alloy at the temperature of the forming side of the magnesium alloy according to any one of items 7 to 9 above, wherein 0, of which is forged, and the temperature of the alloy whose temperature is 2 is cast, the casting In the method (-10-) (5) 200304496, the solution treatment is performed at 380 to 44 ° C for 1-24 hours. 11. The method for forming a magnesium alloy according to any one of items 7 to 10 above, wherein the forging is performed under a strain rate and temperature condition of Z 値 less than 103. The method for forming a magnesium alloy as described in item 1 above is characterized in that a magnesium alloy having an aluminum content of 2-10 mass stars is searched to obtain a casting having a crystal grain size of 30 μπ! Or less. The product is subjected to solution treatment at the solid solution temperature of its composition and the temperature in the solid phase line range, and then forged to obtain a forged product with a crystal grain size of 1 〇μηι #, and then the forged product is further forged into a desired shape. . When a cast product having a crystal grain size of 30 μm or less is subjected to a solution treatment by casting, the second phase particles that are coarse and fragile grain boundaries originally formed during casting disappear, the ductility increases, and the plastic formability improves. By forging a cast product having improved plastic workability by such a solution treatment, it is possible to finely recrystallize the crystal grain size to 10 μm or less by forging to dynamically recrystallize by forging, and further improve its forgeability. Therefore, according to the method of the first item, a cast product having a crystal grain size of 30 μm or less by casting is subjected to a solution treatment, and then the crystal grain size is made to 10 μm or less by forging, and further forged to a desired size. shape. In this method, the aluminum content of the magnesium alloy is preferably 2.5 to 6% by mass, and the casting is preferably performed by a die casting method or a thixotropic die casting method. The solution treatment is preferably performed at 3 80 to 440 ° C for 1-24 hours. After the solution treatment, the forging for miniaturizing crystal grains and the forging for forming are performed at Z 値 109. It is better to perform under the strain rate and temperature of -1013. -11-(6) (6) 200304496 The method for forming a magnesium alloy according to item 7 above, characterized in that a magnesium alloy having an aluminum content of 2-10% by mass is cast to obtain a casting having a crystal grain size of 10 μm or less, and The cast product is subjected to a solution treatment at a solid solution temperature of its composition and a temperature in a solid phase range range, and then forged into a desired shape. When a cast product having a crystal grain size of 10 μm or less by casting is subjected to a solution treatment, although the crystal grains are coarsened, the second-phase particles that are coarse and fragile grain boundaries formed during casting disappear, and the extensibility increases. Improved plastic workability. By forging such a cast product which is improved in plastic workability by solution treatment, it can be formed into a desired shape. Therefore, according to the method of item 7 above, a cast product having a crystal grain size of 10 μm or less obtained by casting is subjected to a solution treatment, and then forged to a desired shape. In this method, the aluminum content of the magnesium alloy is preferably 2 to 6% by mass, and the casting is preferably performed by a die casting method or a thixotropic die casting method. The solution treatment is preferably performed at 3 80 to 440 ° C for 1 to 24 hours, and then forging for forming is preferably performed at a strain rate and temperature of Z 値 less than 10i3. Z 値 refers to the temperature-compensated strain rate representing the relationship between temperature and strain rate. It is a Zener-Hollomon parameter commonly used to express the relationship between the effect of temperature and strain rate on the flow stress. It is defined by formula (I). Zn = ε 'exp (Q / RT) ........ (I) Here, ε' strain rate (sec-i) Q: Lattice diffusion activation energy -12- (7) (7) 200304496 R: Gas constant T: Absolute temperature Q. Because magnesium alloys cannot be obtained, pure magnesium is generally used! 3 5 thousand joules / mole. [Embodiment] Hereinafter, an embodiment of the magnesium alloy forming method of the present invention will be described in detail. First, an embodiment of the magnesium alloy forming method according to the first item will be described. According to the method of the above item 1, a magnesium alloy having an aluminum content of 2 to 10% by mass is first cast to obtain a cast product having a crystal grain size of 30 µm or less. If the content of the magnesium alloy is less than 2% by mass, the corrosion resistance is inferior, and the melting temperature becomes high, which makes it unsuitable for casting. If the aluminum content of the magnesium alloy is more than 10% by mass, the subsequent plasticizing processability cannot be sufficiently improved by the subsequent solution treatment, and a solution solution having excellent forgeability cannot be obtained. Therefore, the content of the coin alloy is 2-10% by mass, preferably 2.5-6% by mass. The casting method of this magnesium alloy is not particularly limited, but in order to obtain a casting with a crystal grain size of 30 μm or less, a die-casting method or a thixotropic die that uses a faster cooling and solidification speed and can refine the crystal grains Good casting method. That is, the gravity casting method generally depends on the thickness of the product, and the solidification of the molten magnesium alloy is slow. Therefore, the crystal grows during cooling and solidification and the crystal grain size is as large as 200 μπι. For example, the die casting method or thixotropic die casting method are used. The casting method of injecting molten or semi-melted casting liquid in a mold has fast cooling and solidification speeds, so that the crystal grains become fine, and can be cast to a crystal grain size of less than 30 μm. 13- (8) 200304496 The products are preferably those with a small crystal particle size, and those with an IS method and alloy composition below 30 μm are generally made of crystal particles. The solution is processed by a crystal with a particle size of 30 μm or less obtained by f seeking. The solution treatment temperature should be the solid solution temperature and the temperature of the composition, and the optimum temperature is 3 80 to 43 0 ° C. When the solution is dissolved at a solid solution temperature or lower than 38 CTC, the plastic workability is hindered due to the precipitation of aluminum or magnesium. If the solid solution temperature exceeds its composition, the liquid phase is generated to hinder the plastic workability. It is advisable that the solution should be dissolved for 24 hours. It is preferable to use a longer time when the temperature is low and a high temperature. By the solution treatment, the knot phase precipitated from the α phase of the mother phase is dissolved in the mother phase. Although the crystal grains of the mother phase are coarsened, the stone phase that slides through the grain boundary of the workability can improve the workability solution. After the treatment, forging is performed to obtain a forged product with a crystal grain size (hereinafter, this crystal grain is also used for miniaturizing crystal grains to refine forging "), and then the forged product is forged to obtain a product (hereinafter, also This is used for forging and forming forging is called "forming forging"). Crystal grain refinement forging refers to those who refine the grain by dynamic recrystallization. The crystal grain refinement is forging or forming the composition of the forged alloy, and the conditions of the crystal grain refinement forging are performed within the range of the forgeable processing conditions. The group of magnesium alloys is in the range of Zn 値 10-9-103, preferably the range of i〇1Q-i〇13. It is better to produce products with a diameter of 15 · 3 0 μιη depending on the diameter of the solid phase line. Treatment of large compounds with small temperatures [or more than 430 hours of treatment time to 1-to reduce the cooling of grain boundaries in a short period of time hinders the effect of plastic. Forging below 10 μm is called "the formation of the desired shape of the foundry product will depend on the magnesium content, but the speed should be -14- (9) (9) 200304496 degrees and temperature Although the conditions of forming and forging also vary depending on the composition of the magnesium alloy, the strain rate and temperature in the range of Z 値 is 1013 or less, preferably 108-1013, and more preferably 109-1012. It is better to carry out under the conditions. If the forging conditions of the micronized forging and forming forging are outside the range of the above-mentioned preferable Z, there may be defects such as breakage and cracking, and forging cannot be performed. Generally, crystals Grain refinement forging system sets the conditions depending on the alloy composition, with the strain rate lO ^ -1OdsecT1, and the temperature range of 200-500 ° C as the appropriate range of the above-mentioned Z. The forming and forging system depends on the alloy composition and sets the conditions, with the strain rate lO ^ -lOdsecT1, temperature 200-40 (The range of TC is an appropriate range of the above-mentioned Z 値. The crystal grain size is reduced to 10 μm or less by forging of crystal grains, and the plastic workability is improved by forging, and it can be formed. Forging. The grain size is 10 μm or less may be sufficient, and generally, forging of crystal grains having a crystal grain size of about ^ i 〇μιη is performed. Next, an embodiment of the magnesium alloy forming method of the seventh item will be described. The method of the seventh item is first A magnesium alloy having an aluminum content of 2 to 10% by mass is cast to obtain a cast product having a crystal grain size of 10 μm or less. If the aluminum content of the magnesium alloy is less than 2% by mass, the corrosion resistance is inferior. 纟 S of magnesium alloy If the content is more than 10% by mass, the subsequent plasticizing process cannot be sufficiently improved by the subsequent solution treatment, and a solution-treated product having excellent forgeability cannot be obtained. Therefore, the aluminum content of the magnesium alloy is 2 to 1% by mass. It is preferably 2-6 mass%. -15- (10) (10) 200304496 Also, the content of components other than aluminum of the magnesium alloy used is the same as that described in the method of the above item 1. Such a magnesium alloy The casting method is to obtain a cast product with a crystal grain size of 30 μηι or less, and a die-casting method that uses a very rapid cooling and solidification speed to refine the crystal grains is preferred. Although the crystal grain size of the cast product is preferably smaller, And below 1 〇μπι That is, depending on the alloy composition used, it is generally cast to a crystal grain size of 5-10 μm. Castings with a crystal grain size of 10 μm or less obtained by casting are based on the solution temperature and solid state of the composition. The solution is treated at a temperature in the range of the phase line to improve workability. The conditions for the solution treatment are the same as the solution treatment of the first method, and the temperature is from 3 80 to 43 0 ° C for 1-24 hours. Preferably, the product is obtained after solution treatment and then forged into a desired shape. The forging is also performed in the same range as the method of item 1 above, depending on the composition of the magnesium alloy and the conditions of the forgeable processing. Although the conditions of forging also vary depending on the composition of the magnesium alloy, it is performed under a strain rate and temperature conditions in which Z 値 is less than 1013, and is preferably in the range of Z 値 10, 10i2. Z 温度 is 1013 The above may cause defects such as breakage and cracks, and cannot be forged. General "Stomach condition" The above forging system sets conditions depending on the alloy composition, and the strain rate lO ^ -lO ^ sec · 1, and the temperature 200-50 (rC2 range can make the above Z 値 into an appropriate range. [Example] -16- (11) 200304496 The following examples are used to illustrate the present invention in detail. The magnesium alloy ingots used in the following examples were produced by adding magnesium and zinc to the commercially available AZ 91 alloy ingot to adjust the composition. AZ8 1-AZ2 1 magnesium alloy ingot. The composition analysis results of the used AZ91 alloy ingot and the produced alloy ingot are shown in Table 1. Table 1 Composition analysis results of alloy ingot (mass%) _ Alloy ingot A1 Zn Mn Si C u Fe Ni Be AZ9 1 8.9 0.70 0.2 1 0.3 10 0.0400 0.0020 0.0004 0.0008 AZ8 1 7.6 0.70 0.30 0.025 0.0010 0.0017 tr 0.0034 AZ7 1 6.9 0.72 0.24 0.024 0.0011 0.0003 tr 0.0019 AZ6 1 5.7 0.79 0.30 0.024 0.0010 0.0029 tr 0.0026 AZ5 1 4.8 0.78 0.29 0.018 0.0009 0.0013 tr 0.0022 AZ4 1 3.6 0.68 0.27 0.013 0.0008 0.0012 tr 0.0014 AZ3 1 2.6 0.60 0.28 0.010 0.0004 tr tr 0.0016 AZ2 1 2.1 0.83 0.28 0.003 0.0052 tr tr 0.0030 Example 1 (1) Casting and solution treatment An alloy ingot of AZ9 1-AZ21 was cut into a thixotropic die-casting wafer for casting. A thixotropic die-casting molding machine JMG-45 manufactured by Japan Steel Co., The maximum injection speed is set to 4m / sec under run-down conditions, and a 1.5mm-thick casting is made by using a box mold with a mold temperature of 25 ° C and a length of 181mm x a width of 255mm and a height of 10mm without a bottom. At that time, because the melting point of each alloy ingot is -17- (12) 200304496, it depends on adjusting the barrel and nozzle temperature, and at the same time discussing the possibility of forming at the same time. The barrel tip temperature of each alloy is shown in the table. 2 〇 Table 2 The barrel tip temperature of thixotropic die casting alloy temperature (° C) AZ9 1 620 AZ8 1 6 18 AZ7 1 619 AZ61 624 AZ5 1 637 AZ4 1 640 AZ3 1 638 The result is AZ9 1 to AZ3 1 may Casting, and the melting point of AZ21 is 64 5 ° C, it can not be cast without melting in the heating boundary of the forming machine. Therefore, the casting boundary of the thixotropic die-casting molding machine for AZ-based alloys is 2.5% aluminum. The measurement of the crystal grain size of the castings obtained by thixotropic die-casting is sampled from the center of each casting and embedded in the resin. After honing, the sample composition was etched with paleoacid or acetic acid-based etchant according to the composition of the sample, photographed with an electron microscope at a magnification of 500 times, and measured in accordance with the slicing method of "Steel ingot crystal grain size test method" of JIS GO 5 22. The particle size is 1.74 times. Further, in order to confirm the effect of the solution treatment, each cast product was heat-treated at 43 0 t for 1 hour, and then the crystal grain size was measured in the same manner. -18-(13) 200304496 These results are shown in Figure 3 or Figure 1. Table 3 Crystal grain size of thixocasting alloy Crystal grain size (μm) Before solution treatment After solution treatment AZ9 1 13.1 28.3 AZ8 1 12.3 —— 19.1 AZ7 1 10.2 16.4 AZ6 1 13.1 24.6 AZ5 1 10.1 13.7 AZ4 1 12.4 20.2 AZ3 1 10.5 17.9 As can be seen from Table 3 and Figure 1, although the crystal grain size before solution treatment is different in composition, the crystal grain size is coarsened after solution treatment. When this system is subjected to a solution treatment, the Θ phase existing at the grain boundaries is dissolved in the ^ phase of the mother phase to coarsen the crystal grains. It is recognized that the crystal grain size is that the casting liquid is rapidly cooled and the solidification speed is fast, and the particle size is small, and the results are as follows. That is, the aluminum content decreases from AZ 9 1 to AZ 3 1 and the melting point increases. Therefore, as the barrel temperature at the front end of the forming machine is increased, 'the rapid cooling effect can be achieved by the temperature difference between the temperature of the prayer solution and the temperature of the prayer mold', there are crystalline particles of AZ91 with a small temperature difference of 28 μηι and AZ51 with a large temperature difference The crystal grain size is 14 μm, and the crystal grain size tends to be smaller. However, in the case of AZ4 1 and AZ3 1, the high-temperature cast solution has the effect of delaying cooling, and thus has a larger crystal grain size of 18-20 μm. In addition, in order to check the plastic workability of the solution-treated product, a tensile test piece was cut from each of the castings -19- (14) (14) 200304496, and the solution was treated at 42 ° C for 1 hour at 300 ° C. The tensile test was performed at a strain rate of 1.0 X lO ^ secT1. The results are shown in Figure 2. From Figure 2, it can be seen that AZ 91 to AZ 71 with a large aluminum content has a lower elongation of 15-24%, AZ. The elongation of 6 1 to AZ 3 1 is more than 40%, and the plastic workability is particularly improved. Therefore, the aluminum content range of the forged casting is 25% by mass or more in terms of castability, and in terms of workability. It is preferably 6 mass% or less. (2) Forging in the above (1), casting the AZ61 to AZ31 cast products by the thixotropic die casting method at 420 ° C for 1 hour, and then cutting 20mm X 20mm The samples were uniformly heated in an electric furnace and placed in a mold that had been pre-heated at the specified forging temperature shown in Table 4, and forged at a certain condition of a strain rate of 3.3 X lO ^ secT1. Test pieces were cut out of the samples after forging. The crystal grain size was measured by the same method as in the above (1), and the results are shown in Table 4. In addition, the strain rate was replaced by The Z 中 obtained in the above formula (I) is shown in Table 4. The Q 适用 applicable for calculation here is 135 / Joules / mole. Table 4 倂 describes each sample before forging (after solution treatment). Crystal grain size -20- 200304496 m! I solution treatment (before forging) Crystal grain size (μπι) 24.6 13.7 20.2 17.9 Crystal grain size (μπι) after forging 350 3.3xl0 · 2 6.9xl09 12.9 10.0 18.8 in 300 3.3χΐσ2 6.7xl010 2 Bu · 10.4 14.2 250 3.3χ10'2 l.OxlO12 * CN o inch · 200 3.3χ10_2 2.7xl013 * * * o T—H 1—Η 3.3xl〇 · 2 1.5xl015 * * * * Forging temperature (.C) 8 Xfl g Lai M m JM N AZ61 AZ51 AZ41 AZ31 mxsi conditions
-21 - (16) (16)200304496 由表4可明瞭下列各點。 亦即，發現在同一鍛造溫度下，鋁含量多之合金經由 鍛造結晶有容易微細化之現象。另一方面，鋁含量多之合 金在較低溫度時鍛造加工中會破損，以實驗之應變速度， 相對於AZ61可於3 00 °C以上鍛造，AZ31亦可於200°C以上 鍛造，而獲得結晶粒微細化之效果。 由該結果可知，可使結晶粒徑進行結晶粒微細化成爲 可超塑性鍛造之10 μιη以下之鍛造條件爲，AZ61至AZ31之 合金爲Ζ値109-1013之範圍，較好爲1〇1()-1〇13之範圍。 選擇藉由上述鍛造，將結晶粒微細化之樣品與未充分 微細化之樣品，切割2 0 m m X 2 0 m m X 1 . 5 m m厚之板狀樣品 ，將該樣品插入鍛造鑄模之下模20mm x 20mm空模中，依 表5所示條件至真應變-1.1，以直徑3mm、高l〇mm之具有 圓筒形凹部之上模锻造成形爲鑄造品之形狀，鍛造加工時 之鍛造性是否良好示於表5。 -22- 200304496 趔·餛wng^ftIsM® In漱 CM 44-ί 500 3.3x10'2 4.4x107 〇 X 〇 〇 〇 〇 < 〇 〇 < 400 3.3x1〇·2 9.9x108 〇 X 〇 〇 〇 〇 X 〇 〇 <3 I 350 3.3x1 cr2 6.9x109 〇 X 〇 〇 < 〇 X 〇 〇 X <5τ5· 300 3.3x1 cr2 6.7x1010 < X 〇 〇 < 〇 X 〇 〇 X 200 3.3x10'2 2.7χ1013 〈丨 X <J <] <J 〇 X 〇 〇 X 150 I- 3.3x10'2 1.5χ1015 X X X X X X X X X X 鍛造溫度(°c) /^S OJ c/D g 滕 M JM Ν Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ 12.9 CN 00 C0 ο ο 18.8 ο Τ— CD 14.2 鍛造 條件 ΑΖ81 ΑΖ51 ΑΖ41 ΑΖ31 蜮雜叔胡侧鹚_ιδ:χ 制妮}f链辁；？唣绷||。螂^^胡侧鹚^^:<1 πππι^^ι^ι^1ό s^i- —l^l^il^l-Γ -23- (18) (18)200304496 由表5可認知下列事實。 於晶界々相易析出，而易阻礙晶界滑動之銘含量多之 組成者必須以較高加工溫度，亦即以較大之Z値才能形成 鑄造品。另一方面，結晶粒徑即使超過1 0 μπι，其合金以 較高之加工溫度亦可形成鑄造品。 然而，工業上若鑄模溫度達40(TC以上，則鑄模耐久 性不佳並不實用。雖使用耐熱性材料或經表面處理亦可改 善鑄模之高溫耐久性，但鑄模成本提高而不理想。 由此結果可知，欲成形爲所欲形狀之鍛造條件， AZ6 1至AZ31之合金爲Z値1013以下之範圍，而以108-1013 之範圍爲佳。 實施例2 (1 )鑄造及溶體化處理 以壓鑄法替代實施例1之觸變模鑄法進行鑄造試驗。 使用與觸變模鑄法成形時相同成形品形狀之鑄模，合金係 直接使用於觸變模鑄成形機中所使用之同樣進料之合金錠 ，並不先作成晶圓者。使用日本東芝機械製DC 65 0 tCLS 冷室壓鑄成形機，設定鑄液溫度7〇0°C，高速時之射出速 度5.0m/sec，鑄模溫度250 °C之條件依序進行鑄造。各鑄 造品之尺寸 '形狀係與實施例1相同。 觸變模鑄法無法成形之AZ2 1材以壓鑄法亦可進行鑄 造。此係因壓鑄法並非如觸變模鑄成形機般於成形機之機 筒內將材料熔融，而係於與成形機分開設置之給液裝置中 -24- (19) 200304496 將材料熔融，因而熔融溫度可高達700 °c，而可使熔點高 之AZ21亦融熔之故。 各鑄造品係與實施例1同樣操作並測定溶體化處理前 後之結晶粒徑，結果示於表6及第3圖。又，溶體化處理係 於43 0°C進行1小時。 表6 壓禱禱造品之結晶粒徑 合金 結晶粒徑（μ m ) 溶體化處理前 溶體化處理後 ΑΖ9 1 7.3 14.9 ΑΖ8 1 6.4 13.1 ΑΖ7 1 7.0 13.8 ΑΖ6 1 7.8 15.2 ΑΖ5 1 6.9 10.4 ΑΖ4 1 6.1 11.3 ΑΖ3 1 5.7 9.5 ΑΖ2 1 5.8 9.7 由表6及第3圖可知，壓鑄鑄造品之結晶粒徑較觸變模 禱禱造品之結晶粒徑爲小’即使不經結晶粒微細化之锻造 處理，在溶體化處理前已小於1 〇 μηι。推論此係因成形機 之充塡速度快而有急冷效果之故。 (2 )鍛造 -25- (20) 200304496 所得之鑄造PDP由於，結晶粒既已微細，因此爲使鑄造品 之鍛造容易’以與實施例i中觸變模鑄之鑄造品之結晶粒 微細化之鍛造相同之條件進行鍛造，試驗是否可進行無裂 痕之鍛造。對溶體化處理前之樣品進行預備鍛造試驗則因 於晶界析出之Θ相甚厚’不易產生晶界滑動，而易產生裂 痕。此種傾向以鋁含量多者更爲顯著。因此僅以溶體化處 理後之樣品進行試驗。結果示於表7。此時之樣品係自壓 鑄鑄造品切割2 0 m m X 2 0 m m X 1 . 5 m m厚之板狀，並將該樣 品以一定之應變速度成形。鍛造之真應變爲-1 . 1。 -26- 200304496 zm 鍛造性A 350 I 3.3x10_2 6.9x109 X < < 〇 〇 〇 〇 〇 300 3.3x10'2 6.7x1010 X < < 〇 Ο 〇 〇 〇 250 3.3x10"2 1.0x1012 X X < < 〇 〇 〇 〇 200 3.3x10-2 2.7x1013 X X X < <] 0 〇 〇 150 3.3x10-2 1.5x1015 X X X X X X X X 鍛造溫度(。C) /-"S 8 C/3 g 滕 Μ m Ν ΑΖ91 ΑΖ81 ΑΖ71 ΑΖ61 ΑΖ51 ΑΖ41 ΑΖ31 ΑΖ21 鍛造 條件 塑迤壊鹚_饑·· 〇 担痣^到、賴翦： *-21-(16) (16) 200304496 Table 4 shows the following points. That is, it has been found that at the same forging temperature, an alloy with a large amount of aluminum is likely to be finerly refined through forging crystals. On the other hand, alloys with a large amount of aluminum will break during forging at lower temperatures. Based on the experimental strain rate, compared with AZ61, it can be forged above 300 ° C, and AZ31 can also be forged above 200 ° C. Effect of miniaturizing crystal grains. From this result, it can be seen that the forging conditions for making the crystal grain size finer and smaller than 10 μm that can be superplastic forged are that the alloy of AZ61 to AZ31 is in the range of 値 109-1013, preferably 10 ( ) -1003 range. Select the samples for which the crystal grains have been refined and the samples that have not been sufficiently refined by the above forging, cut 20 mm X 20 mm X 1.5 mm thick plate-shaped samples, and insert this sample into the lower mold of the forging mold 20mm x 20mm empty mold, according to the conditions shown in Table 5 to true strain -1.1, 3 mm in diameter and 10 mm in height with a cylindrical recessed part is forged into a shape of a cast product, whether the forgeability during forging Good results are shown in Table 5. -22- 200304496 趔 · 馄 wng ^ ftIsM® In wash CM 44-ί 500 3.3x10'2 4.4x107 〇X 〇〇〇〇〇 &400; 400x × 10 2 9.9x108 〇X 〇〇〇〇〇 X 〇〇 < 3 I 350 3.3x1 cr2 6.9x109 〇X 〇〇 < 〇X 〇〇X < 5τ5 · 300 3.3x1 cr2 6.7x1010 < X 〇〇 < 〇X 〇〇200 3.3x10 ' 2 2.7χ1013 <丨 X < J <] < J 〇X 〇〇X 150 I- 3.3x10'2 1.5χ1015 XXXXXXXXXX Forging temperature (° c) / ^ S OJ c / D g Teng M JM Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ Γ 12.9 CN 00 C0 ο ο 18.8 ο Τ— CD 14.2 Forging conditions AZZ 81 AZ51 AZ41 AZZ 31 蜮 杂 叔 胡 鹚 鹚 ιδ: χ 制 妮} fchain 辁;? Stretched ||.螂 ^ 胡 侧 鹚 ^^: < 1 πππι ^^ ι ^ ι ^ 1ό s ^ i- —l ^ l ^ il ^ l-Γ -23- (18) (18) 200304496 From Table 5, we can recognize the following fact. Compositions that are prone to precipitate at the grain boundary, and those with a large content that are likely to hinder the grain boundary sliding, must be formed at a higher processing temperature, that is, a larger Z 较大. On the other hand, even if the crystal grain size exceeds 10 μm, the alloy can form a cast product at a higher processing temperature. However, in the industry, if the mold temperature reaches 40 ° C or higher, the durability of the mold is not good. Although the high-temperature durability of the mold can be improved by using heat-resistant materials or surface treatment, the cost of the mold is not ideal. From this result, it can be seen that forging conditions to be formed into a desired shape, the alloy of AZ6 1 to AZ31 is in the range of Z 値 1013 or less, and preferably in the range of 108-1013. Example 2 (1) Casting and solution treatment The die-casting method was used instead of the thixotropic die-casting method of Example 1. The casting test was performed using the same mold shape as that of the thixotropic die-casting method, and the alloy was directly used in the thixotropic die-casting molding machine. Alloy ingots without first making wafers. Using a DC 65 0 tCLS cold chamber die-casting machine made by Toshiba Machinery of Japan, set the temperature of the casting solution at 7000 ° C, the injection speed at high speed is 5.0m / sec, and the mold temperature Casting was performed sequentially at 250 ° C. The size and shape of each casting was the same as in Example 1. AZ2, which cannot be formed by the thixocasting method, could also be cast by the die-casting method. Thixotropic die casting Generally, the material is melted in the barrel of the forming machine, and it is placed in a liquid feeding device separately from the forming machine. -24- (19) 200304496 The material is melted, so the melting temperature can be as high as 700 ° c, and the melting point can be high. AZ21 is also melted. Each casting product was operated in the same manner as in Example 1 and the crystal grain size before and after the solution treatment was measured. The results are shown in Table 6 and Figure 3. In addition, the solution treatment was performed at 43 0. ° C for 1 hour. Table 6 Crystal grain size of the pressed prayer product Crystal grain size (μm) Before solution treatment After solution treatment AZ9 1 7.3 14.9 AZ8 1 6.4 13.1 AZ7 1 7.0 13.8 AZ6 1 7.8 15.2 AZ5 1 6.9 10.4 AZ4 1 6.1 11.3 AZ3 1 5.7 9.5 AZ2 1 5.8 9.7 As can be seen from Table 6 and Figure 3, the crystal grain size of the die-cast casting is smaller than the crystal grain size of the thixotropic mold prayer product. The forging process after crystal grain refinement is less than 10 μηι before solution treatment. It is inferred that this is because of the rapid cooling effect of the forming machine and the rapid cooling effect. (2) Forging-25- (20) 200304496 Because the obtained cast PDP has fine crystal grains, The forging of the product is easy. The forging is performed under the same conditions as those for forging the crystal grains of the thixotropic die-casting casting in Example i, and the test is performed for crack-free forging. The sample before the solution treatment is performed. The preliminary forging test is because the Θ phase precipitated at the grain boundaries is very thick, and it is not easy to cause grain boundary sliding, and it is easy to generate cracks. This tendency is more significant for the aluminum content. Therefore, only the samples after solution treatment are used for testing . The results are shown in Table 7. At this time, the sample was cut from a die-casting casting to a thickness of 20 mm x 20 mm x 1.5 mm, and the sample was formed at a constant strain rate. The true strain of forging is -1.1. -26- 200304496 zm forgeability A 350 I 3.3x10_2 6.9x109 X < < 〇〇〇〇〇300 3.3x10'2 6.7x1010 X < < 〇〇 〇〇〇〇250 3.3x10 " 2 1.0x1012 XX < < 〇〇〇〇200 200 3.3x10-2 2.7x1013 XXX < <] 0 〇〇150 3.3x10-2 1.5x1015 XXXXXXXX Forging temperature (.C) /-" S 8 C / 3 g Teng M m Ν ΑZO91 ΑZO81 ΑZ71 ΑZ61 ΑZ51 ΑZ41 ΑZ31 ΑZ21 Forging conditions are plastic _ hungry · 〇 bearing mole ^ to, Lai 翦: *
蜮雜4<胡侧鹚_鷂·· X ¾潜七胡删_ _繇： V -27- (22) (22)200304496 由表7可認知下列事實。 亦即，與溶體化處理前之樣品同樣，若鋁含量多則有 鍛造性惡劣之傾向，於應變速度3.3 X lO^sec·1之條件下 ，AZ91至AZ71即使將加工溫度提高至3 50 °C以上，進行鍛 造時亦會產生缺陷。但若鋁含量減低則鍛造變佳’雖然 AZ91在任何溫度下其鍛造品均會產生破損，但AZ81在300 °C以上（亦即Z値小於6.7xl01G) ，AZ71在250°C以上（亦 即Z値小於1.0x1 〇12 )則不會產生裂痕，但產生小破損。 此外，若鋁含量減低則可鍛造而不會產生缺陷， AZ6 1、AZ5 1 及 AZ4 1 在 25CTC 以上（亦即 Z 値小於 1 · 〇x 1 〇 12 )，AZ31與AZ21在200 °C以上（亦即Z値小於l.OxlO13 ) 則鍛造品不會產生缺陷而呈現優良之鍛造成形性。 由上述結果可謂將結晶粒徑鑄造成爲1 0 μιη以下之壓 鑄鑄造品之鍛造適宜組成爲鋁含量2_6質量％，而適宜之鍛 造條件爲Ζ値小於l.OxlO13者。 〔發明之效果〕 如上述，依據本發明之鎂合金之成形方法，於可鑄造 且鍛造性優越之鎂合金組成中，藉由組合鑄造與鍛造使鎂 合金成形，而能以高良率製造具有複雜而精密之形狀，且 物性之可信度高，耐蝕性亦充分足夠之製品。 【圖式簡單說明】 第1圖係示實施例1之觸變模鑄鑄造品（溶體化處理後 -28- (23) 200304496 )之結晶粒徑圖示。 第2圖係示實施例1之溶體化處理品於3 00 °C，ε’= 1.0 χ 1 (Γ2 s e (Γ 1之拉伸試驗結果。 第3圖係示實施例2之壓鑄鑄造品（溶體化處理後）之 結晶粒徑圖示。 -29-Miscellaneous 4 < Hu Shouxun_ 鹞 ·· X ¾ Qianqihu delete_ _ 繇: V -27- (22) (22) 200304496 From Table 7, the following facts can be recognized. That is, similar to the sample before the solution treatment, if the aluminum content is large, the forgeability tends to be poor. Under the condition of a strain rate of 3.3 X lO ^ sec · 1, AZ91 to AZ71 increase the processing temperature to 3 50 Above ° C, defects may also occur during forging. But if the aluminum content is reduced, forging becomes better. 'Although AZ91 will damage its forged products at any temperature, AZ81 is above 300 ° C (that is, Z 値 is less than 6.7xl01G), and AZ71 is above 250 ° C (that is, If Z 値 is less than 1.0x1 〇12), no cracks will occur, but small damage will occur. In addition, if the aluminum content is reduced, it can be forged without defects. AZ6 1, AZ5 1 and AZ4 1 are above 25CTC (that is, Z 値 is less than 1 · 〇x 1 〇12), and AZ31 and AZ21 are above 200 ° C ( That is, if Z 値 is less than 1.0xlO13), the forged product will have no defects and exhibit excellent forging shape. From the above results, it can be said that the suitable composition for forging a die-casting cast product having a crystal grain size of 10 μm or less is an aluminum content of 2-6 mass%, and the suitable forging conditions are those where Zn 値 is less than 1.0xlO13. [Effects of the Invention] As described above, according to the magnesium alloy forming method of the present invention, in a magnesium alloy composition that can be cast and has excellent forgeability, the magnesium alloy can be formed by combining casting and forging, and it can be manufactured with high yield. A product with a precise shape, high reliability, and sufficient corrosion resistance. [Brief description of the drawing] Fig. 1 is a graph showing the crystal grain size of the thixotropic die casting product (after solution treatment -28- (23) 200304496) in Example 1. FIG. 2 shows the results of the tensile test of the solution-treated product of Example 1 at 300 ° C, ε ′ = 1.0 χ 1 (Γ2 se (Γ 1). FIG. 3 shows the die-cast casting product of Example 2. Schematic diagram of crystal grain size (after solution treatment). -29-